Auth bypass in Kestra
CVE-2026-53577
Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the previewFileFromExecution endpoint (GET /api/v1/{tenant}/executions/{executionId}/file/preview) contains an access control bypass that allows any authenticated user to read output files from any other execution within the same tenant, bypassing execution-level and namespace-level isolation. This vulnerability is fixed in 1.0.45 and 1.3.21.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (35.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 35.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Kestra
- Kestra-Io Kestra — versions < 1.0.45, >= 1.1.0, < 1.3.21
Weakness classification (CWE)
References
- github.com/kestra-io/kestra/security/advisories/GHSA-r6v3-xxwj-9h42 (Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-53577?
- CVE-2026-53577 is a medium-severity vulnerability in Kestra, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-06-26.
- How severe is CVE-2026-53577?
- Medium severity. CVSS v3 base score is 6.5 out of 10.